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1
by brian
clean slate |
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drop table if exists t1,t2; |
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create table t1(str varchar(10) default 'def',strnull varchar(10),intg int default '10',rel double default '3.14'); |
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insert into t1 values ('','',0,0.0); |
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select default(str), default(strnull), default(intg), default(rel) from t1; |
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default(str) default(strnull) default(intg) default(rel) |
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def NULL 10 3.14 |
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explain extended select default(str), default(strnull), default(intg), default(rel) from t1; |
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id select_type table type possible_keys key key_len ref rows filtered Extra |
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9 |
1 SIMPLE t1 system NULL NULL NULL NULL 1 100.00 |
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Warnings: |
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11 |
Note 1003 select default('') AS "default(str)",default('') AS "default(strnull)",default('0') AS "default(intg)",default('0') AS "default(rel)" from "test"."t1" |
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select * from t1 where str <> default(str); |
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13 |
str strnull intg rel |
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14 |
0 0 |
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explain select * from t1 where str <> default(str); |
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id select_type table type possible_keys key key_len ref rows Extra |
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17 |
1 SIMPLE t1 system NULL NULL NULL NULL 1 |
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18 |
drop table t1; |
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19 |
CREATE TABLE t1 (id int(11), s varchar(20)); |
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INSERT INTO t1 VALUES (1, 'one'), (2, 'two'), (3, 'three'); |
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SELECT s, 32 AS mi FROM t1 GROUP BY s HAVING DEFAULT(mi) IS NULL; |
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22 |
ERROR HY000: Field 'mi' doesn't have a default value |
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23 |
DROP TABLE t1; |